1. Technical Field
The present disclosure relates to an apparatus for the lifting of vehicles. More particularly, the present disclosure relates to a jack for elevating a chassis of a vehicle.
2. Background of Related Art
Jacks are widely used to elevate the chassis of an automotive vehicle in a variety of environments. The lift plate of the typical prior art jack apparatus is positioned beneath a lift point on the chassis and the jack is actuated to raise the vehicle for the replacement of a flat tire, for example. Problems with jacks occur, however, when maintenance needs to be performed on the vehicle and the distance between the chassis of the vehicle and the ground is less than the distance from the lift plate of the jack, positioned at the lower limit of its range of motion, and the ground. In this all too common situation, the prior art jack apparatus cannot be positioned under the chassis to perform the repair without additional effort expended by a motorist or pit crew to lift the car above the lift plate of the jack. This kind of scenario can occur as a result of a simple flat tire and can be compounded by uneven ground, a worn suspension system, a low clearance configuration of the chassis relative to the ground, wheel size, location of the lift point in relation to the outside edge of the chassis, and loading of the vehicle.
FIGS. 1 and 2 illustrate a conventional jack shown generally as 200. Jack 200 includes an actuation lever 234, a pair of side support plates 212, a lift arm 220, a stabilizing arm 250, a lift plate 222, and a roller 214. Actuation lever 234 is positioned at the proximal end of jack 200 and roller 214 is positioned at the distal end. Side support plates 212 include a linear upper edge which slopes downwardly at an angle beginning near the proximal end of jack 200 and extending to the distal end of jack 200. A proximal pivot member for lift arm 220 and stabilizing arm 250 is supported between side support plates 212.
The configuration of support plate 212, lift arm 220, and stabilizing arm 250 of jack 200 results in the distal portion of lift plate 222 protruding above side support plates 212 when lift arm 220 is positioned at the lower limit of its range of motion. The height of lift plate 222 above ground in combination with its position relative to side support plates 212 makes it difficult in many circumstances to position jack 200 under the chassis of a vehicle. The lowest position of lift plate 222 also places stabilizing arm 250 below side plates 212 adjacent the ground. This makes the lowest position of jack 200 vulnerable to undulations in the ground or variations in a gravel surface. In addition, lift plate 222 contains a lip 223 that further limits its application by necessitating that the added height of lip 223 clear the lift point of the vehicle for proper vertical positioning beneath the lift point of the chassis.
Jack 200 is also constrained by the angle of side support plates 212 when interior lift points of a vehicle are inset from the edge of the chassis. Under these circumstances, lift plate 222 may fit under the vehicle, but the angle of side support plate 212 can preclude jack 200 from extending far enough under the vehicle to reach the lift point. Thus, the configuration of the prior art jack is distinctly limited in its ability to gain access beneath a vehicle and consistently engage the lift points of a vehicle chassis to perform its intended function.
A continuing need exists for a jack configuration that minimizes the height between the ground and lift plate and supports accessing the lift point of a chassis from an approximately horizontal direction in order to increase its ability to lift an automotive chassis under adverse circumstances when the height of the chassis of a vehicle is close to the ground.
A jack apparatus is provided that includes a unique lifting mechanism and side support plate configuration which allows a heretofore unachievable reduction in the height of the lift plate when it is at the lower limit of its range of motion. The side support plate includes a first angled portion that tapers towards the ground, a horizontal portion, and a second angle that further reduces the height of the distal end of the jack and thereby supports the installation of the jack between the chassis and the ground when the chassis of a vehicle is low to the ground. When the lifting mechanism is positioned at the lowest limit of its range of motion, the totality of the lifting mechanism is positioned beneath and between the side support plates. In addition, the lift plate includes a tapered guide channel which enables the jack to be self-aligning during placement of the jack beneath the chassis of a vehicle.
The invention, together with attendant advantages, will be best understood by reference to the following detailed description of the invention when used in conjunction with the figures below.